Anhydrous non-alcoholic antiperspirant products are presently the most popular form of deodorants since they are the best accepted by consumers. This acceptance is due primarily to three factors, i.e., they have a low irritation potential, great antiperspirant efficacy, and go on dry so that they are non-sticky. Typical anhydrous non-alcoholic antiperspirant products comprise a dispersion of an antiperspirant active agent in a base comprised essentially of volatile silicones. The most commonly used antiperspirant active agents are aluminum or aluminum/zirconium acid salts. The present antiperspirant market is divided about equally among roll-on, stick and aerosol-type formulations. The most rapidly growing form is the stick since it has the most acceptable properties for application to the underarm.
Although the presently-sold products are excellent and represent advances over aqueous or alcohol-based products, they suffer from one major deficiency--their efficacy as deodorants diminishes rapidly after about twelve hours after application. While efforts have been made to overcome this deficiency by the addition of antimicrobial agents to the product to prolong deodorant action, these efforts have failed to produce long-acting deodorant compositions.